Q&A with Neil Gemmell

The goals for Predator Free NZ were ambitious but do you think it’s possible for the project to meets its targets by 2050 using current methods and technologies?

“The goal is ambitious but achievable in my view. Current technologies (poisons and trapping) would get us a long way. We have already shown this through eradication efforts of rats on islands.

“However, to do something at a larger scale, relatively quickly, cheaply and with minimal impact on other species, will require the development and adoption of new approaches.”

One of the goals of the project is to do with technological development. What potential advances could help Predator Free NZ meet its targets?

“There are likely four areas of key technological development:

1. Genetic based approaches that target a species’ specific vulnerability, for example, targeted mutations in key developmental and reproductive genes to make a pest species produce offspring that are all male or infertile.

2. New attractants and toxins that are specific to a given species, which will enable us to make poison baits that are attractive to and toxic to a specific animal. It’s likely that these developments will be assisted by new genomic data.

3. Establishment of better ways to detect pest species in our environments using, for example, a network of biosensor devices that would send a digital signal each time they encounter a pest species. This would enable a more targeted approach to eradication.

4. Establishment of a citizen science movement in support of the challenge. This would be integral to the eradication effort via deployment of traps, toxins, etc. within their communities and also engage these citizens in the active monitoring of outcomes, such as tracking the reductions in pest numbers and the increases in other flora and fauna.”

The use of genetic engineering has been mentioned as a potential avenue to the eradication of pests. What possible technologies does this encompass and how might these work?

“I suspect genetic technologies will be the key to developing pest control that is species-specific, works at a large scale, and is cheap and persistent.

“Fundamentally these will predominately focus on exploiting genetic weaknesses in a given species, and I suspect key areas to target will be around reducing reproductive potential so that populations cannot persist.

“Prior work surveying people’s view on issues such as possum control suggests that there is more public support for tools that might impair an animal’s fertility compared with any other form of manipulation or control measure that may cause the animal harm and suffering.

“There are multiple approaches through which we can proceed, with some showing more promise than others. One possibility we developed a few years ago, and continue to work on, is call the Trojan Female Technique (TFT). This is a non-GMO approach that exploits naturally occurring variants.

“The idea derives from the maternal inheritance of the mitochondria that occur in the cells of all animals and plants. Mitochondria are the ‘batteries’ of the cell, providing the energy needed for the cell to carry out all of its essential processes.

“We have discovered that inherited variation can cause a decrease in the energy output of these batteries. This occurs naturally among individuals in most species. Most cells have low energy requirements and lots of mitochondria, so a decrease in the energy output of the mitochondria doesn’t normally affect them.

“However, a unique exception is sperm. Sperm have high energy requirements and very few mitochondria, so that males carrying some mitochondrial variants can have compromised (or no) fertility. This effect has previously been recognised as a potential threat to small populations of endangered species and is a known cause of human male infertility.

“We want to turn this concept on its head, and purposefully use it to reduce the breeding output of pests and thus the size of the populations that they can grow to. Put simply, we would introduce females carrying mitochondrial variants known to affect male, but not female, fertility as a means of achieving population suppression and eventual eradication. Current work in fruit flies shows considerable promise.

“One of the great things about this approach is that it theoretically could work in almost any species because mitochondria are common to all higher life forms. [There are more details on this work here].

“Another strategy gaining momentum is the idea of genetically modifying animals so that they produce all male offspring. It’s likely we will be able to do this for mice within a few years because we know the genetics of that system well.

“The idea is to produce mice that carrying the SRY gene, the key sex determining gene in most mammals, linked to a so-called gene-drive that effectively ensures that 9 out of 10 offspring will be male. The idea has promise, but there are many unknowns as to whether this will work in mice, whether the idea can transfer to other species, and whether society is ready to accept a tool that involves genetic modifications that are predicted to race through populations.”

What are the barriers to using genetic techniques to control pest populations?

“There are two major barriers. The first, and most important, is the social acceptability of this technology, and this will likely be governed by multiple things including the perceived benefits versus threats. We will need to do a lot of work in these areas over coming years to quantify the risks and benefits of such strategies to inform the discussions.

“The other major barrier is technological. Genetic engineering of mice is well established, but we are much less able to genetically engineer rats, despite them being relatively similar. Manipulations of possums, stoats and other pests will likely be more of a challenge than many people anticipate. Yes, we have new gene editing technologies (e.g. CRISPR-CAS) that speed this process up, but what we are talking about here will be a lot of work. If we are serious about this endeavour we need to get organised and start planning out what the workflow for this project would look like over the next decade plus.

“The first target of eradicating a pest species by 2025 is only eight years away, this is likely going to be hard to achieve. If we start today we need six months to plan, likely several years in the lab, then a few years for controlled field trials, before eventual deployment at landscape scales, which will take massive effort and years to achieve eradication.

“This is the New Zealand version of the space-race and we need commitment and resource to achieve this. Likely a quasi-business/military model as seen during the space-race might be needed to achieve this goal.”

Will we need legislative change to utilise genetic technology to meet this challenge?

“I suspect we will have to modify some of our legislation. Under our Hazardous Substances and New Organisms Act (HSNO) gene editing is viewed as a genetic manipulation and this likely will need to be reviewed as in many other countries (e.g. USA).

“Simple gene editing is not considered a modification. We may also have to soften our stance on release of GMOs into the environment if we are to achieve the Predator Free 2050 goal. This, of course, will require robust discussion in public fora.”

Are there any promising alternatives to using genetic engineering?

“There are species specific toxins that look promising. However, deployment of these on massive scales is costly and the cost would be ongoing as they do not persist.

“At this stage, I see few options better for achieving long-term control than those based on some form of genetic-based control, most of which would require development of GMOs.”

The New Zealand Government has announced its Predator Free 2050 initiative to eradicate the pest species of rats, stoats and possums by the year 2050. Control measures that potentially utilise genetic modification/editing are now being discussed; what are some of the pros and cons of genetic engineering for pest control?

“The pros of genetic intervention are that: methods are specific to the target species, they can be extremely efficient, and there is no animal suffering.

“On the other hand, the drawbacks are that these applications are technically difficult, requires actively releasing pests, and is faced with public scepticism.”

What sort of genetic technologies might be effective in eradicating invasive mammals?

“Population suppression requires spreading sterility or biasing the sex ratio. If most potential mates are sterile, the population goes down. If most organisms are born male, the population goes down.

“But because releasing additional invasive mammals is environmentally damaging, candidate technologies will have to release many fewer animals than the current invasive population. Gene drives, which are capable of actively spreading in the population from an initial introduction, are good candidates.”

Has your work identified any risks associated with potential genetic control measures?

“There are two basic kinds of gene drive: those that will affect a local population and then stop, and those that are likely to spread globally. Standard CRISPR-based gene drives are extraordinarily efficient at copying themselves, so it takes very few escaped organisms for them to spread.

“To be blunt, I am highly sceptical that these global drive systems can be reliably contained, and strongly recommend against their use for conservation.

“Local CRISPR-based drive systems such the “daisy drives”, which my lab are developing, are still early in development. [For an explanation of ‘gene drives’ and ‘daisy drives’ see video.]

“It’s important to note that humanity has no experience engineering systems anticipated to evolve outside of our control. We’re developing nematode worms, which reproduce twice per week and are readily grown in the hundreds of millions, as a model in which to study gene drives in the laboratory. Since evolution is a numbers game, we need to run experiments on populations of comparable size to those we anticipate affecting in the wild in order to predict the behaviour of these systems once released.

“CRISPR-based gene drive systems are unfailingly detectable by sequencing, spread slowly over generations, and are readily blocked and overwritten in the event that something goes wrong. However, we haven’t yet demonstrated a way to reliably restore populations to their original genomic sequences, though we’re actively working on it.”

Are genetic pest solutions being used or considered elsewhere in the world?

“Releasing sterile insects is a very common strategy that goes back decades, beginning with radiation-sterilised screwworms. Several projects are currently releasing genetically sterile mosquitoes. Some projects used engineered sterile males, others use males that have been artificially infected with Wolbachia, a naturally occurring parasitic bacterium that renders male mosquitoes sterile when they mate with an uninfected female.

“The Eliminate Dengue project is releasing fertile male and female mosquitoes infected with a strain of Wolbachia that blocks transmission of dangerous viruses; Wolbachia then spreads through the local mosquito populations by benefiting infected females, which can successfully mate with any male and reliably pass Wolbachia to their offspring.

“There have been no releases of engineered gene drive systems, but several laboratories are actively building gene drive constructs of various kinds in mosquitoes, flies, and schistosomes (a parasitic blood fluke responsible for schistosomiasis/bilharzia/snail fever).”

What would your advice be to New Zealand when considering the possibility of genetic technologies? How important will social acceptance of such tools be?

“When engineering ecosystems: 1) Make the smallest possible change capable of solving the problem 2) Start local and scale up only if warranted

“Even if New Zealand rats carrying a global suppression drive did not successfully stow away on ships before eradication, someone would almost certainly smuggle them out. After all, rats are a tremendously economically damaging pest elsewhere in the world, so many people have cause to eliminate them, even if it requires illegal transport.

“Most importantly, any unauthorised release of a global drive system would likely be devastating for public trust in scientists and governance. Judging by past examples of scientific accidents and misconduct, the backlash would likely result in delaying applications by at least a decade.

“How damaging would that be? There’s no way to know for sure, but judging by current trends in malaria control and vaccine research, delaying the popularly supported release of gene drive systems against malarial mosquitoes would almost certainly result in millions of unnecessary deaths, mostly of children under the age of 5. And that’s just malaria; never mind effects of delaying the direct medical applications of CRISPR.

“Given the potential consequences of an escaped or deliberately smuggled global drive system, I strongly recommend waiting for local drive systems when it comes to conservation.

“Equally important is the last rule:

3) Research that could affect the shared environment should be open and community-guided. Conducting gene drive research behind closed doors denies people a voice in decisions that could affect them. It’s not just the right thing to do, it’s also the most likely to lead to safer and more satisfactory outcomes.

“Scientists aiming to alter the shared environment – especially with gene drive – should not only make their work public, but actively invite concerns and criticism. Not only do local residents know their own environment best, they may well think of something that professional scientists would otherwise miss.

“Studies have shown that risk analyses performed by professional analysts together with community members yielded more comprehensive results than the professionals alone… as judged by the professionals.

“Applied science exists to serve society. If New Zealanders are going to lead the world in genetic invasive species removal – as you have in the use of conventional methods – demand openness and community guidance from the very beginning.”

Q&A with James Russell

The goals for Predator Free NZ were ambitious but do you think it’s possible for the project to meets its targets by 2050 using current methods and technologies?

“It would not be possible today to eradicate from New Zealand the eight species of mammalian predators which are the target of Predator Free NZ 2050 (PFNZ). This is precisely why the ‘deadline’ for this aspirational goal is so far out (33 years).

“The methods and technologies we have today allow us to control and eradicate invasive mammalian predators from some very large areas (10,000+ hectares) but we are limited by only having a few tools which we know work, and these few tools also only work in particular environments (e.g. uninhabited forested areas). The challenges to achieving PFNZ by 2050 are thus more than simply scaling up what we’re currently doing.”

How important is it that we get this right? What is at stake and how will NZ benefit from these outcomes?

“It’s critical that we ramp-up our efforts to preserve our native species in order to prevent any more of them going extinct. It is no longer sufficient just to rely on their conservation in the ‘back-country’ in the face of pervasive threats such as invasive species and climate change. It is, therefore, important that we find solutions for their conservation which have longevity and provide good returns on conservation investment. Otherwise, we risk wasting labour and resources. To that end, we do have to make sure PFNZ is implemented properly, so that it doesn’t have unintended side effects, or distract or delay from other urgent conservation issues.

“It won’t just be New Zealand’s native species that benefit from PFNZ though. Benefits of eradicating these eight mammals will also extend to primary industries – where invasive pests are vectors of disease – as well as offer boosts to tourism and public health. Generally, the economic benefits of eradicating these eight species are predicted to outweigh the costs, especially when you consider that we already invest millions every year in their control just to stay in a ‘holding pattern’.”

Will PFNZ simply be a case of scaling up from island eradications, or will there be new challenges to address? What have we learnt from island eradications that can be applied to the mainland?

“In the first instance (e.g. PFNZ 2025 interim goals) PFNZ will focus on scaling up what has worked so well on islands for the past 50 years, and seeing how it can be applied to ‘mainland’ areas, such as peninsulas. For example, knowledge already exists about the best combination of methods to remove a target species, and how to best prevent mammal reinvasion, whether it’s by swimming or hitchhiking or crossing a fence.

“However, new challenges exist around how to control multiple species at once across very large areas with very mixed habitats. This is particularly the case when we want to control or eradicate pests around inhabited areas. As we develop new tools and methods to address these challenges, these will eventually feed back into our island eradications, allowing us to eradicate these species from islands where it is not currently possible for technical or social reasons (e.g. Great Barrier Island and Stewart Island).”

What do you think the most effective tools will be to effectively eradicate the target species?

“It’s most likely that for each species a suite of tools will have to be used in combination to achieve successful eradication across very large landscapes. This is already the case for most mammal eradications on islands, where a single method alone is not usually sufficient. An exception to this has been rodent eradication, where a single tool (rat poison) has been sufficient to achieve 100% eradication. The challenge ahead is thus developing new tools and finding which ones work best in combination together, and identifying where the market gaps are for product development and investing in those areas.

Will any social or legislative changes will be required in order for NZ to utilise the tools necessary to achieve these Predator Free goals?

“Predator Free New Zealand will require the majority of New Zealanders to support it for it to become viable. This shouldn’t require any major social change, as already over 99% of New Zealanders agree we can’t do nothing about these predators, but it will require all of us to engage in discussions about both the science and emotions relating to pest control, and some of these discussions won’t always be easy.

“Following these discussions, we will need to look at some of the legislation in New Zealand. The Wildlife Act of 1953 is now 64 years old and literally comes from a different time in our thinking about conservation. We will have to ensure that policies and legislation are in place to enable efficient pest control which remains socially and ethically acceptable, and that also facilitates the use of new technologies, without too much red-tape associated with it. One of the biggest barriers to developing new pest control technologies is the costs for developers associated with regulatory compliance.”

Q&A with Andrea Byrom

Dr Andrea Byrom Ecologist and Director of the Biological Heritage National Science Challenge

The goals for Predator Free NZ were ambitious but do you think it’s possible for the project to meets its targets by 2050 using current methods and technologies?

“It’s not possible for the project to meet its targets using current methods and technologies. New Zealand is a world leader in seeking creative ways to apply pest control cost-effectively, but it will be too expensive to scale up current approaches. Instead, we will need to be able to roll out new technologies that are extremely cheap, humane, acceptable to the public, and can be coordinated across the country (hundreds of thousands or even millions of hectares). It’s going to be a huge step up and a whole new ball game.”

How important is it that we get this right? What is at stake and how will NZ benefit from these outcomes?

“Our economy is highly reliant on our environment, and on our ‘clean green’ environmental image. The tourism industry, for example, relies on attracting international visitors to our gorgeous landscapes; the farming community relies on ecosystem services provided by our land and water. Both are compromised by the presence of pest animals, and some of these effects are not always visible to the average person.

“For example, we know rats are common throughout our native forests, and that they munch their way through millions of native birds, lizards and iconic invertebrates like weta every year. Those impacts are not ‘in your face’, so we forget they are happening. Our native species perform vital ecosystem functions, but slowly they are declining or becoming extinct, and their ecosystem functions will gradually disappear too.

“The landscape the tourists have come to love will look and feel very different in just 20 to 30 years unless we do something drastic. If we take this challenge on, however, we will be the envy of the world – we’ll look like a bold and gutsy little nation that stood up for its environment and its sense of identity and said: ‘We want this; we care about our native species and we want to be unique’.

“It’s a pretty powerful vision, and thousands of people all around the country have already made this commitment in the form of restoration planting or pest control in their backblocks and backyards.”

The announcement of the initiative came with additional funding; what sorts of technologies or programs should be advanced in order to get an effective technology mix?

“People always ask about the new technologies for killing pests or reducing their populations to extremely low numbers. There is no question that we will need new tools in the toolkit. For example, we will need to re-consider biological control, which is a catch-all term for approaches like causing infertility in mammals or using a virus to reduce a population to very low levels.

“There are also promising new methods such as ‘gene drives’ that are being discussed, which are a new method of breeding an all-male line into a pest population until eventually it declines to extinction with no females to breed with. This all sounds futuristic and scary to most people, but the reality is that there are many technological hurdles to overcome in the world’s laboratories before we can apply these technologies in a field situation (many years down the track), and when we do take them to the field, we could trial them on a remote island first, which would guard against any risk of an unwanted organism escaping.

“I would prefer that we take a step back and consider the wider picture, and in my mind there are issues other than a technological ‘fix’ that are equally important. For example: will we need to alter legislation to allow the release of a virus or new organism into the environment? How should we make use of existing tools in the toolkit, as well as developing new ones? Should we begin with peninsulas or islands, and how should we ‘roll out’ predator-free status across the North and South Island? How will we respond to public concerns about new technologies? How will other pests respond when rats, stoats and possums are removed? And how can we incentivise the level of investment required to make PFNZ a reality?

“All these questions point to the need for a ‘whole system’ approach: thinking about all the pieces of a gigantic jigsaw puzzle together rather than one piece at a time. But it will be worth it.”

Are there any promising technologies on the horizon that NZ should be considering as part of its arsenal?

“Yes, there are. The NZ’s Biological Heritage National Science Challenge has already invested in research to progress some of them, for example ‘biosensors’ that can be placed in the bush to detect stoats or rats; new super-effective smelly ‘lures’ that are irresistible to pests; and species-specific toxins that only target rats or possums but are benign to other animals such as dogs or livestock.

“We have also put a ‘watching brief’ on gene drives and are working with international collaborators in Australia and the US to take advantage of this new technology in the future.”

How important will public buy-in and support be to achieving the PFNZ goals?

“Public buy-in and support will be vital. In a free-thinking society, we can’t necessarily expect everyone to believe in the vision immediately, but I hope that eventually, it will be as routine to have a rat trap in your backyard or shed as it is to brush your teeth in the morning.

“The trick will be to coordinate all these localised efforts at a national scale, and much effort will now need to go into coordinating pest control efforts at a regional and local level also. And while the public’s support and commitment will be crucial, it’s not sensible to believe that private citizens or community groups alone will be able to deliver on the vision – even with the best will in the world.

“The government’s commitment to getting the vision out there and recognised is important, and we now need to put a concerted effort into incentivising the massive investment required and coordinate that expenditure at a regional and national level, to achieve the vision.”

Q&A with Carolyn King

The goals for Predator Free NZ were ambitious but do you think it’s possible for the project to meets its targets by 2050 using current methods and technologies?

“No, but ongoing improvements and wider use of current technology are essential to minimise short-term damage to vulnerable populations. We must do whatever we can to protect what is left of our heritage from continuing stress, otherwise, by the time it becomes possible to achieve eradication, there may not be much left.

“We must accept that at this stage, pests removed can always be replaced, so pest control is like cleaning toilets, you just have to keep on doing it. Above all, it’s important not to get carried away with ideas that turn out to be impractical, as these exhaust everyone’s emotional capital and lead them to give up. There is no need to despair, only to be realistic, and patient.”

How important is it that we get this right? What is at stake and how will NZ benefit from these outcomes?

“It is vital that we all understand the essential distinction between short-term damage prevention, which is feasible now, and long term eradication, which is not – at least not yet. We must not confuse these two quite different goals.

“We must resist the temptation to be disappointed that achieving eradication is much further off than the other, and at the same time recognise the huge significance of repeated, temporary damage-prevention operations to hold the line until new technology and social change makes at least local eradication possible.”

What do you think the main challenges will be to eradicating the target species?

“Without any doubt, the main challenge is to accelerate fertility control or, if possible, render impossible any breeding and reinvasion of the pests removed. Killing pests is easy and getting easier – but the most important thing is not how many are killed, but how many were left, and how quickly those that are removed can be replaced.

“Preventing that is MUCH more difficult, which is why we still have pests after centuries of throwing everything we can think of at them.”

Are there any promising technologies on the horizon that NZ should be considering as part of its arsenal?

“There are lots of promising technologies on the horizon, and no-one can predict at this stage which will be most significant long-term, except that it can’t be more of the same. We can’t just keep finding more and better ways to kill pests. It is likely to be as different from what we are doing now (and have been doing for ages) as the electron microscope is from the light microscope – a completely radical approach that we can’t now imagine, and it may be discovered quite accidentally in the course of looking for something else.”

What needs to change (ie. legislative, social etc) in order to increase the chances of Predator Free 2050 being a success?

“Pest control is already allowed in law, although new techniques will have to get their own scrutiny. Biggest change must be in social attitudes – (1) getting people to think in populations not individuals, so to understand that an unavoidable cost of some dead birds does not invalidate a good method and is acceptable if the breeding rate of the population benefits. This is, of course, a matter of proportion, and careful monitoring; (2) getting everyone involved, because anyone who offers a refuge to even a few pests, e.g., by refusing to cooperate with a local programme or allow access to their private property, will effectively prevent success and impose a cost a huge financial loss on the community. This is very likely to happen in communities where conservation values run a distant second to other more pressing concerns, especially child poverty, drug use and sporting interests.

Q&A with Charles Daugherty

The goals for Predator Free NZ were ambitious but do you think it’s possible for the project to meets its targets by 2050 using current methods and technologies?

“Yes, I think it might be possible to achieve a Predator Free New Zealand using current methods, but it would be extremely labour-intensive and costly. New methods will make the task cheaper and quicker, exactly as happened with the Human Genome Project. New technologies developed during the course of the Human Genome Project in the 1990s not only resulted in the project being completed ahead of schedule, but also meant that a private company completed the entire human DNA sequence about the same time as the multi-government consortium that had initiated the project.

“The technology to reach and land on the moon did not exist when the project was announced in the early 1960s, but new technology allowed the goal of landing by the end of the decade to be achieved.”

Various government and charitable groups were already undertaking extensive pest control prior to the announcement of Predator Free 2050. How will Predator Free 2050 work with existing efforts?

“A key task for Predator Free 2050 is to bring together, coordinate and harness the energies of the hundreds (maybe thousands) of community environmental initiatives, ensure that existing programmes are integrated into the new initiatives and programmes required to achieve the goals of PF2050. Education programmes in schools already help to educate the public about the need for this work.”

The announcement of the initiative came with additional funding; how is that funding going to be distributed and what sorts of technologies or programs are likely to be prioritised?

“The funds will be allocated by the new board of nine members of Predator Free 2050 Ltd. appointed at the end of 2016. They will establish criteria for allocation of funds, but it seems clear that they will focus on landscape-scale programmes, new technologies, and programmes that leverage additional funding from business, philanthropists, and local governments.

“To succeed, we need visionary programmes that use new technologies, engage new support, and operate on a big scale.”

Are there any promising technologies on the horizon that NZ should be considering as part of its arsenal?

“I’m sure there are promising technologies on the horizon, but I can’t provide specific examples that are ready for immediate use.

However, research is actively underway on at least the following: new chemical lures to attract predators to traps; new types of traps, including those that are self-resetting, or that use wireless technologies to notify that the trap has been sprung; genetic pest-control technologies focused on individual species. It’s likely that some of these and other novel methods will be critical in achieving the PF 2050 goal.”

How important will public buy-in and support be to achieving the PFNZ goals?

“Public support is, in many respects, the single most important key to success. New programmes to educate the public to understand the need for predator removal and the many benefits that will arise from doing so will need to be implemented in coming years. Many schools already contribute significantly. People often do not understand, for example, that doing nothing regarding introduced pest species is a decision to impose large ongoing costs on all New Zealanders – for example, on our national wealth arising from dairy, horticulture and tourism.

“Doing nothing is also a decision to violate our national and international commitments. The New Zealand Biodiversity Strategy 2000 – 2020 commits us to stopping the decline of indigenous biodiversity. Internationally, New Zealand has been a party to the Convention on Biological Diversity since 1993. This commits us to the same goal – halting the decline in indigenous biodiversity, and predator control is a key element of achieving this goal.

“We have a simple choice as a nation: eradicate the most dangerous introduced predatory species, or accept that they will eradicate our native species. Only New Zealanders can save our rarest and most unique species, which, like the kiwi, are often national symbols.”

Q&A with Phil Seddon

The goals for Predator Free NZ were ambitious but do you think it’s possible for the project to meets its targets by 2050 using current methods and technologies?

“No, the overarching goals of the initiative cannot be met by current methods. The need for new tools is acknowledged by the Government’s interim goal of developing a scientific breakthrough capable of eradicating one small mammalian predator by 2025.

“Simply placing more traps will not be sufficient because we can’t cover enough area effectively, that is we can’t access all the areas containing predator pests, can’t service the hundreds of thousands of traps required, and can’t be sure of trapping the last individuals in any area.

“Nor can we dramatically increase the use of poisons because of increased risks of by-kill of native species, and importantly, because of public resistance to having more poison dropped from the sky.”

The use of genetic engineering has been discussed as a potential avenue to eradication of pests. What possible technologies does this encompass and how might these work?

“The ability to read, write and manipulate genetic material has increased astoundingly in recent years. The arrival of the efficient and cost effective gene editing tool CRISPR has transformed our ability to modify individual animals and even entire populations.

“It is now theoretically, and soon practically, possible to genetically engineer pests to produce sterile offspring, to produce only male offspring, or to produce offspring that die before they can breed [see attached paper – “Is It Time for Synthetic Biodiversity Conservation?”]. The release of suitably genetically modified individuals into wild populations could result in that population slowly breeding itself out of existence – no need for traps or poisons.”

What are the barriers or risks to using genetic techniques to control pest populations?

“Take the risks of GMO crops and livestock, then imagine that the modified organisms will not be confined to field or paddock but will be released to range freely in the environment. Environmental release of GMOs introduces new levels of risk and uncertainty, such as unanticipated expression of new genetic sequences, or the undesirable transfer of the modification to other species.

“A major barrier will be public acceptance in the face of the ‘Monsanto effect’, whereby GMOs are seen as being tied to big business and driven by corporate interests rather than having environmental and human health concerns a priority.”

Is it important that such tools are socially accepted?

“This is essential and will be a perhaps bigger challenge than even getting the technology right. We need a careful, controlled, early and successful case study to allay public fears and to demonstrate how environmental release of a GMO might be beneficial for conservation – perhaps getting rid of the mice on a small offshore island, where there are natural barriers to dispersal and the ability to apply conventional control to eradicate the mice should things not work out as planned.

“I think the general public might be more accepting of GMOs for conservation than some people think – we need to give an informed public a chance to consider the issue.”

Are there any promising alternatives to using genetic engineering for pest control?

“Traditional biological control, such as some species-specific pathogen, remain on the table, but I’m not sure these are ‘promising’, and they certainly carry significant risks of their own. The NZ public has a wariness of biological control because, again, it involves environmental release and carries significant unknowns – and after all, we have ferrets, stoats, and weasels because they were thought to be suitable biological control agents for rabbits.”

Conflict of interest statements

Neil Gemmell

A) AgResearch endowed my chair, but have no role in governing my research or position.

B) I currently have funding to pursue some aspects of the work outlined below (notably work on Trojan Females and Gene Drives) as part of the biosecurity control programme run as part of the Biological Heritage NSC. I may stand for my research interests to benefit further if some of these ideas mainstream into PFNZ2050.

Kevin Esvelt

Because I publicly described CRISPR gene drive technology and its capabilities, I hold myself morally responsible for the consequences.

I am a listed inventor on several patents filed by Harvard and MIT on CRISPR-based gene drive systems, which I currently hope to leverage in order to require open research and adequate safeguards in this field. I have no commercially relevant interests and favour a temporary moratorium on for-profit applications of the technology.

My laboratory is currently exploring the possibility of building daisy suppression drive systems that would spread infertility in mice and rats, though we have not yet begun experiments in these organisms. We will make our plans publicly available and invite comments and criticism, including from New Zealand, before we begin.

James Russell

10% of my salary is paid for by Zero Invasive Predators. I am the project leader for an MBIE grant on high tech solutions to invasive mammal pests (Biological Heritage National Science Challenge). I have previously received funding from the Department of Conservation.

Andrea Byrom

None declared.

Carolyn King

None declared.

Charles Daugherty

I have some relevant connections that are not conflicts, including:

Trustee, Predator Free New Zealand. This is different from and preceded Predator Free 2050); our chair is Sir Rob Fenwick, who is also on the board of PF2050 Ltd. PFNZ was formed about three years ago to develop the concept of a predator free NZ and advance the concept in the public arena.

Board member, Zero Invasive Predators Ltd. This is a company formed with a grant from the NEXT Foundation and co-funding from the Department of Conservation to develop new technologies for detection, eradication, and exclusion of predatory mammalian species.

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The Science Media Centre will next month take its popular science video making workshops to Christchurch and Dunedin, offering more researchers the chance to get science video savvy. These Science Media SAVVY workshops focus on giving scientists the tools and skills to communicate their research in 90 second videos aimed at an online audience... >> Read Full Post